Page 1 of 2 12 LastLast
Results 1 to 13 of 16
  1. #1
    Join Date
    Sep 2008
    Location
    Pittsburgh,PA
    Posts
    64

    Trouble with a Dunham Bush Compressor

    I have a Dunham Bush chiller M#HRSC255DQ with 4 Hitatchi screw compressors. I am having a problem with one of the compressors. The compressor will sometimes load 100% and other times it will only load up @ 50-60% even though the load solenoid has 120volts and the leaving water temp keeps rising above setpoint. The compressor continues to operate unloaded with 148 degree suction bell temp, 4 degree superheat, and the discharge line temp keeps rising tripping the compressor on high oil temp. Anyone have any ideas?

  2. #2
    Join Date
    Sep 2008
    Location
    Yes, I mentioned it before, Georgia.
    Posts
    13
    your metering device, is having problems.

  3. #3
    Join Date
    Jan 2005
    Location
    USA
    Posts
    1,460
    Way to vague. More info will help greatly. Superheat, subcooling, water inlet and outlet temps, actual pressures not tranducer readings, amp draws versus rated and maybe more. I have had the displeasure of working on a few DB screw chillers and many here may be able to help.

    BUT first you need to get your post count up to 15 then apply for a pro membership. Trust me it is worth your efforts to get the membership. You will find a huge amount of info available here but be forewarned this site is like crack once you get a taste your hooked.
    "It's always controls"

  4. #4
    Join Date
    Sep 2008
    Location
    Pittsburgh,PA
    Posts
    64
    My superheat was 4 to 5 degrees, subcooling was 16 degrees, suction pressure was 63psi, discharge pressure was 217psi, inlet water temp was 54 degrees and leaving was 46(three compressors were on) and amperage was between 63 and 69 amps

  5. #5
    Join Date
    Sep 2003
    Location
    Western PA
    Posts
    1,369
    Bowhunter21. Welcom to the site.

  6. #6
    Join Date
    Jan 2005
    Location
    USA
    Posts
    1,460
    Quote Originally Posted by bowhunter21 View Post
    My superheat was 4 to 5 degrees, subcooling was 16 degrees, suction pressure was 63psi, discharge pressure was 217psi, inlet water temp was 54 degrees and leaving was 46(three compressors were on) and amperage was between 63 and 69 amps
    Good info. Keep posting. Yes welcome to this site sounds like you will not have any trouble getting your pro status. DB's are fun huh. Where do you get parts for them there.

    Does this chiller have the retarded display mounted on the door with a layer of circuit boards behind it and about 10 other cpu boards like AI/AO and DI/DO and com and so forth and so on.

    I had a lot of fun with those one summer.
    "It's always controls"

  7. #7
    Join Date
    Feb 2007
    Posts
    25

    Slipper seal is leaking by

    Sounds like your slipper seal is leaking by, Manual load compressor to 100% and then put in hold if the percentage of load drops you slipper seal leaks and you need to replace pain in the ass to do how many hours are on the compressor you my want to replace compressor

  8. #8
    Join Date
    Sep 2008
    Location
    Pittsburgh,PA
    Posts
    64
    Do you know where I can get a manual for that compressor

  9. #9
    Join Date
    Jan 2005
    Location
    USA
    Posts
    1,460
    Try this http://www.accscompressor.com/ it was listed on Hitachis web site.
    "It's always controls"

  10. #10
    Join Date
    Sep 2008
    Location
    Pittsburgh,PA
    Posts
    64
    Thanks I will check it out

  11. #11
    Join Date
    Dec 2007
    Posts
    16
    Thanks for the link, i need the manual as well

  12. #12
    Join Date
    Sep 2008
    Location
    long island
    Posts
    2
    Bowhunter, I have worked on these compressors. Call the manufacturer they're very helpful. There are two sizes and believe it or not they will refer to them as the big one or the little one. From my understanding their layout is close. There are tests you can run to determine if you problem is in the solenoids or the slide valve. From what you said it could be a few things, one make sure your charge is right. A low charge will raise your oil temp and also prevent you from loading the compressor fully. The other is a leaking unloading valve or leaking load valve. There should be three total. These can be checked by bypassing discharge gas into one of the ports on the side of the compressor through your manifold. A temperature change in your capillary tubes on the side of the compressor indicate a hung or leaking solenoid. If all prove well then your slide valve needs to be cleaned and the slipper ring needs to be replaced. The job isnt so bad, but I recommend buying two slipper rings in case you wreck the first one (theyre cheap) Instructions are very detailed from the manufacturer it isn't hard just tedious. Good luck

  13. #13
    Join Date
    Sep 2008
    Location
    Pittsburgh,PA
    Posts
    64
    Thanks for the info, it is very helpful. From what I have been hearing sounds like it is a bad slipper ring!

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event